The Rise of Wood EnergyPublished on 07.23.2020
10 min read
Wood: A Source of Energy and the Basis of Green Chemistry
Wood was one of the first materials used by humans in prehistoric times for heating, hunting, making weapons and building homes. It then provided the first molecules for green chemistry. The Egyptians and other inhabitants of the Mediterranean region already knew how to produce plant-based tar 2,000 to 3,000 years ago using the exudate of resinous trees such as pines and firs. This substance, mixed with plant fibers, could be used to waterproof hulls of boats as part of the caulking process. Traces of plant-based resins have been found on ancient ceramics and amphorae, which they helped waterproof.
Craftsmen quickly discovered that when they distilled pine resin, it resulted in a solid, odorless product (rosin) and a volatile, odorous product (turpentine). Mixing the rosin with linseed oil created varnishes of such resistance, flexibility and plasticity that Stradivarius, the famous violin maker of Cremona, used it on his violins. His instruments have more than stood the test of time, as they generally have not changed after 300 years. Turpentine quickly made its mark as a highly effective solvent for grease and wax. The lacquer that has long been used in Asia is also made from resin and the sap of various shrubs, such as acacia gum.
From the mid-18th century onward, wood was the of the Industrial Revolution, before the widespread use of . It powered the steam boiler furnaces and provided the structure for the first machines, cars and planes. It also gave rise to the chemistry industry. Wood was such an indispensable raw material that it was overexploited, and at the beginning of the 19th century people realized that forests were disappearing. To protect this resource in France, a tree-planting policy was reintroduced 150 years after being launched by statesman Jean-Baptiste Colbert to secure supplies of naval timber. Other fuels were then called on to make up the shortfall. This ushered in the coal era followed by the age of oil, with all the polymer and plastic applications that came with it.
The Strong Comeback of Wood
Today, we are seeing a revival of wood due to its renewable nature, which makes it valuable in containing the CO2 emissions of fossil fuels and therefore in fighting .
Twenty-first century technologies have made it possible to perfect all the various uses made of wood over the previous centuries. They have helped us understand the very complex chemical reactions between rosin and linseed oil, for example. Projects are now underway to produce premium varnishes. Of course, they will be more expensive than those made from oil, but they will also be much more effective from both a technical and an environmental perspective.
The need for second-generation biofuels, which are not produced from food crops, has led to new research into wood use. A pilot plant in Bazancourt in the east of France has been working in this area since 2008 as part of the Futurol project.
The paper industry, which is still a big user of wood, was also able to gradually isolate very pure cellulose fiber. The processing segment, using the sulfite process, can manufacture many derivative products, from explosives such as nitrocellulose to emulsifiers for food (e.g., ice cream) and even excipients for drugs. In France’s Landes region, there is a plant owned by the Rayonier paper group, which is now the global leader in the sector.
It should be noted that industrial paper mills are increasingly turning toward this biorefinery and are therefore no longer discarding by-products. In particular, they can retrieve the tannins, which are used in the leather and ink industries, and tall oil, which is used in the pharmaceutical, chemical, cosmetic and other industries.
I won’t go into the details of the other positive factors that may encourage the return of wood or cardboard, like reduced use of plastics in certain products (cutlery and plates) or new architectural designs that avoid using cement.
An Industry Creating Jobs
The rebirth of this industry has two interesting features:
- It has all the technology it needs to produce in large quantities without threatening our forests. People have also formed the habit of replanting trees after logging. There are currently 16 million hectares of forest area in France – double that of the early 19th century. Of course, this isn’t the case everywhere in the world.
- The industry represents almost 400,000 jobs in France. There is a large network of training centers all across the country, including three engineering schools in Nantes, Épinal and Cluny and many great vocational high schools evenly spread throughout the various regions.
Nevertheless, the industry is struggling to attract young people. There are too many misconceptions about wood trades, even though they are becoming increasingly technological and the career opportunities are booming.
Bertrand Charrier is a Professor at the University of Pau and Pays de l’Adour. He heads a team at the Mont-de-Marsan-based French Institute of Analytical Sciences and Physical Chemistry for the Environment and Materials (IPREM) – a joint research unit between the university and the CNRS. He is also coordinator of XYLOMAT, a national network that brings together various players for R&D projects, project development and a range of services related to bio-based materials.
The Solid Position of Wood Within the Global Energy Mix
Wood used to produce heat through combustion, known as wood energy or firewood, is increasingly in demand throughout the world, particularly in Europe and Africa. In the 1980s, no one could ever have imagined this becoming a trend. However, over the last decade or so, energy specialists and economists have started reconsidering the value of wood as a fuel.
In Europe, we are receptive to the fact that wood is a local, source that doesn’t give off CO2 emissions if production is properly managed. Wood energy could therefore help meet the ecological transition objectives set by the European Union. Used alongside solar and wind power, it can respond quickly and effectively to fluctuations in supply.
Wood is an essential resource in many southern countries, particularly in sub-Saharan Africa. Even in towns that have access to gas, and even in the richest households, wood and are still the cooking and heating fuels of choice in Africa, while gas is considered dangerous. It will take a long time to convert to wood, and we may not ever manage to convince everyone.
Will this high demand really be a problem? An idea often put forward by the general public is that using wood energy affects forests and is therefore harmful for the environment and the climate. But research does not support this popular misconception.
Sustainable Forest Management in Europe
Wood has been widely used in Europe for centuries. You would think that the Landes, Sologne and Morvan forests in France have been around forever. However, they were actually modeled and some even created by humans to provide wood for buildings, boats, heating and, nowadays, paper pulp. It is now accepted that forests can serve multiple purposes, including wood production, conservation, carbon storage, land reserves and recreational areas. This realization has led to sustainable management, bringing together appropriate planning and silviculture practices, where (re)planting is playing an increasingly important role. As a result, 78 million hectares of forest have been planted and cultivated, and this number continues to rise due to higher demand for wood energy, particularly in Eastern Europe.
A Lack of Silviculture in Africa
Wood energy is often associated with deforestation in Africa, which is unfair as it is mainly collected during field openings or as part of the fallow cycle. In other words, deforestation is essentially a by-product of agricultural expansion. Admittedly, in certain areas, particularly around large cities where there is high demand, the collection of wood energy is gradually destroying forests. However, clearcutting is rarely or never done for wood energy in Africa, whereas it sometimes occurs in Europe.
Additionally, there is a lack of sustainable management and active silviculture in African forests, which too often also serve one single, exclusive purpose: lumber production or biodiversity conservation. Other uses, first among them firewood production, are completely ignored or unequivocally rejected. For this reason, outside of South Africa, there are hardly any forest plantations (8 million hectares in the whole of sub-Saharan Africa) and those that do exist are negatively viewed, limiting their growth.
The resulting approach typically borders on schizophrenic, with one thing encouraged in Europe yet discouraged in many African countries, particularly as regards forest planting for energy. There are several arguments used to justify this:
- “Creating energy plantations and managing them sustainably is expensive.” Yes, these woodlands are definitely more costly than non-regulated natural forests. However, we should be asking why countries agree to spend so much on subsidizing household gas, oil and the majority of , but not wood energy plantations!
- “Forest plantations only have one specific purpose, little biodiversity and require lots of water.” Of course, all plantations need water and sunlight, and have an “artificial” quality, but no more, and maybe even less, than corn, cassava and sugarcane fields.
- “Wood energy plantations require a lot of land – ideally good land – and therefore have to compete with land needed for food.” This argument overlooks the fact that the need for household energy is vital and should be placed on the same level as the need for food. What is the point in growing corn if you don’t have fuel to cook it?
To summarize, unless we provide all sub-Saharan countries with nuclear power plants or large hydropower facilities and electric stoves, or import huge quantities of gas deep into the continent, there are currently very few alternatives to wood. Examples of energy plantations can be found all over the world that successfully meet growing demand and take the pressure off natural forests. They range in size from Brazil’s large, highly criticized plantations to Ethiopia’s and Madagascar’s village plantations, which are greatly appreciated by local communities. Over the past ten years or so, short-rotation plantations have also been developed in Central Africa, but only on a small scale.
Wood alone is not a miracle solution. The future undoubtedly lies in an intelligent combining solar, wind, hydro and imported gas, but wood is essential in the medium term. There is an urgent need to develop dedicated plantations throughout the world that are adapted to local circumstances.
Laurent Gazull is an agronomist and Ph.D. in geography who serves as a researcher at the French Agricultural Research Center for International Development (CIRAD), which specializes in the of tropical and Mediterranean regions. His work is mainly focused on spatial analysis (localization, social and spatial interactions, modeling), bioenergy value chains (wood energy, biofuels, bioelectricity) and the use of natural resources.